Notes from the heart of perception
Experiential Engineering at the University of Warwick
Coventry, 16 February 2011

Blog Home Page
  • The experiential maze
  • Sound principles
  • Objective data is inadequate
  • The sound of silence
  • Sound is information
  • Electric vehicles and feedback
  • Refinement and power
  • A sound is worth a thousand pictures
  • Engineering requirements
  • Sounds can change the perception of space
  • Healing soundscapes
  • Experiential conclusion
  • Straw men

    The experiential maze

    Electric cars, soundscapes, intensive care units, fountains, psychoacoustics and feelings. This blog is about experiential engineering and why we care passionately about it whether we know it or not.

    Radio four was getting lost in the moral maze as I navigated my way home. I was more than usually aware of what was going on around me in the experiential process of driving. I was dealing with varying speed limits. I was feeling hungry. I was glancing at the satnav. I was listening for its instructions. I was wondering about vibrations from the road surface. I was noticing the lighting conditions. I was thinking about the price of new tyres. I was enjoying the new lumbar support in my seat. I was occupied with unravelling my thoughts about the lecture I had just attended and why I had enjoyed it so much.

    There was so much right with Professor Paul Jennings’ presentation that I wondered how I would communicate its absolute relevance in a way that would resonate with anyone who reads this blog.

    Sound principles

    All the while, on the car radio, the moral maze confused itself with the meanderings of astonishingly small minded but magnificently large ego’d people. To my ears they seemed to be coming from the outlying extremes of reason. As I joined the program they were trying to define what constitutes a valid relationship, how to measure it and who should and should not recognise it. In spite of its distraction potential, it all seemed to be contributing to my thought process and immersive experience as I began to gather my wits.

    In so many subjective discussions about what other people ought to do, why do we all get so steamed up about our own perspective that we can't see through the fog?

    As Professor Jennings had talked about Experiential Engineering, the small hairs stood up on the back of my neck. He used the very same words I use to express my ideas in The Trousers of Reality. Balance. Context. Perspective. Feedback. Effectiveness. Modelling. I was listening. By the Irish definition of a ‘sound man’ as 'someone who says what you are thinking', Professor Jennings is a sound man in every sense of the phrase.

    Objective data is inadequate

    The goal of experiential engineering is to understand the human perspective as well as the functional perspective. To this end the team at Warwick University boasts experts in Design, Information Technology, Psychology, Health, Ergonomics, Physics and Business.

    They aim to make effective and efficient use of developer, user and customer reaction to improve decision making in product and environment development. They combine objective measures with the subjective feedback from their sound labs.

    Engineers rely on numbers, metrics and measures. As you will know if you have read my work, I think our experience of reality is a bit more complex than some of the things that can be measured and that we sometimes need to dig a bit more deeply.

    When Professor Jennings showed us some slides of visual representations of a set of objective measurements of sound, I started chuckling appreciatively into my beard. I am comfortable in this territory and I could guess what was coming next.

    Rock music looks pretty complex as an objective model. Classical music looked more complex. Car engine sounds were extremely visually complex.

    Now came the coup de grace. Jennings explained that if a piece of music is subjected to this type of metrics then the objective measurements are the same whether it is played forwards or backwards. Objective measurement fails to recognise the huge subjective difference.

    The same can be said of anything that has a subjective aspect to its interface. Because of the importance of subjective models in our interactions with technology and our environment, we need a lot more to guide our design decisions than traditional objective measures.

    The sound of silence

    One of the features of Electric vehicles is that they do not make the same noise as the internal combustion engine. I have driven an electric car and it is a spooky experience as it silently moves away and accelerates with a slight hum. You get used to it very quickly though, as you become aware of the road and wind noise. Naturally I prefer this to the roar of a Jag or the power beat of a Harley Davidson, given my general antipathy to status symbols. Hooray say I, but I am in a minority it seems.

    There are worries that this silent running is a safety hazard. There has been some research done which apparently indicates that EVs (electric vehicles) are twice as likely to be in accidents when they are slowing, stopping, reversing or entering parking spaces. Engineers who have spent years making cars quieter are now finding that they are required to make electric vehicles noisier. Indeed it looks like there may soon be legislation requiring them to be noisy.

    Sound is information

    Of course this is not as daft as it sounds. Sound is information. Sight, sound and touch are the ways we interact with the world.

    The sound of a car carries information about whether it is working properly, when to change gear, what brand it is, warnings to pedestrians and cyclists and more.

    Not being a natural car enthusiast I was fascinated to find out just how important the individual sounds are to a brand. Although I suppose it is not all that surprising, really.

    As a result Professor Jennings and his team have been analysing car sounds to find out what exactly it is we like about what we like. They are particularly interested in where 'what we like' and 'what is useful' coincide. It appears to be an interesting journey.

    Electric vehicles and feedback

    There was interesting talk about EVs and the possibilities of internal and external sound systems that would carry useful data as feedback to the driver and the outside world. We have the opportunity to decide what we want the cars of the future to sound like and consequently the soundscapes of our cities and towns.

    WMG have some interesting things to say on their website about their Elvin project.

    Refinement and power

    The team is currently examining how the sounds cars make affect our experience of them. They have analysed the sounds that people expect from their cars. Most people would find a sports car noiselessly accelerating to top speed to rather defeat the point of having a sports car in the first place.

    Car sounds live somewhere in a matrix of power and refinement.
    The perfect sound is one that the major manufacturers seek, as alchemists once sought the philosopher’s stone.

    Normally cars leave me a bit uninterested. The sounds they make are noise to me. I spend a lot of time looking for places where engines cannot be heard.

    A sound is worth a thousand pictures.

    They found that subjective reactions were different to expected targets. They had analysed and measured the car sounds people professed to like. They mapped them onto the matrix of refinement and power. They set a target to produce sounds which people would like.
    Objectively this should have been more like a certain brand A and less like a certain brand B, but perceptions change with context. When they put people in rooms with the technology to create the sound of any car in real time, they found that they did not like the sound of a brand A but they did like the sound of brand B. The subjective experience was rather different from the objective prediction. More importantly it was context dependent and depended on more than just the sound.

    This gap between the objective targets and subjective reactions is the heart of the matter for Professor Jennings.

    Engineering requirements

    The Warwick team have developed a sophisticated system that allows them to model the whole audio visual experience of driving. They broke the sounds down sufficiently to allow them to model engineering changes. E.g. how certain alterations to the suspension or other factors would affect the sound and what effect that has on the overall subjective experience. This allows engineers to make sophisticated changes and measure the subjective reactions of customers without committing to costly engineering in the real world.

    They found that the very things that engineers were trying to optimise could often be making the subjective experience worse. In my career as software engineer I saw this sort of thing happening with many “must have” requirements from designers, stakeholders and customers. When the rubber hits the road, the customers/users do not need or even really want them.

    In one experiment they found that variations in sound that bothered experts were imperceptible and unimportant to their customers.

    There is a huge lesson to be learnt here. Professor Jennings echoed the sentiments of many IT consultants and developers including myself, when he stated that the problem was that the people making the design decisions were not the people who would be using the product. The decision makers tend to have different opinions than users.

    Sounds can change the perception of space

    We touched on the subject of psychoacoustics - the scientific study of sound perception.

    We considered the stakeholders of urban soundscapes. On one end of the scale we have planning authorities and legal guardians against nuisance and on the other those who consider the sounds of our towns and cities to be part of their heritage. Somewhere in the middle are the users of the space. There are merchants who recognise that the sound of bustle is good for business and the residents who want the sound to harmonise with their lives. Someone mentioned Vancouver where fountains are used to mask the sound of traffic. Genius, said the driver in my head.

    Healing soundscapes

    Apparently the sounds in an intensive care unit affect the recovery time of people and sounds in care homes can be helpful in treating people with dementia. Excessive noise has even been linked to heart disease especially in the workplace.

    The Warwick team are working with PHEE (Participation in Healthcare Environment Engineering) to discover what a positive healthcare soundscape is and how to achieve it. They are involving staff and working with the NHS.

    Driving the difference home

    The most astonishing fact of the evening was when we learned that in tests, using hybrid cars over the same route, there was an 87% variation in fuel economy between the best and worst drivers.

    This means that driver education and effective feedback from the vehicle could potentially be more effective than any mechanical fuel efficiency in the engineering of the car. The team at Warwick are looking into which elements of driver behaviour have most effect. They are examining how experience, expectations, personality and aggressive or conservative driving styles affect fuel economy and how to help them.

    Experiential conclusion

    The good professor continued to infect the, shamefully small, but rapt, audience with his rationality and I could continue to give blow by blow accounts of what he had to say. Instead I will give my thoughts on what I thought were the important points to be gathered from it all. These are unashamedly subjective given the subject of the blog.

    • Emotional response affects our perception of experience. This is context driven. Interactive simulation techniques which facilitate engagement, as proposed by the Warwick team, seem to me to be a valuable evolutionary step in understanding requirements of all sorts and matching them with functionality and aesthetics.
    • First experience is not necessarily a good indicator of how perception actually changes with use. This fuels my growing contempt for focus groups, pop polls, forced demographics and shoddy modelling.
    • While much the research has been focused on the technology, it seems that the largest variable in fuel economy and emissions is the driver. As engineers and solutions providers of all sorts we need to be much more restrained about assuming purely technical solutions. We need to check for more obvious, more humanly integrated solutions. In this case education and feedback-cues around fuel consumption and driving styles would appear to be a research direction well worth exploring.
    • Given my own training and expertise, it does not surprise me how much sound affects our perception of reality. It is one of the major representational systems we have along with sight, touch and taste. I applaud any efforts to recognise that objective measures, while vitally important, do not give us the full picture, even in such solid domains as motor engineering.

    Straw men

    On my drive home the the "Moral Maze" wound on. Only one panel member seemed to recognise that his experience and viewpoints were subjective. He had valiantly tried to map that knowledge onto the inevitably subjective experience of homosexual people, elderly people and single parents by imagining walking in their shoes for a mile. He was making a quixotic stand to have the subjective value of permanent relationships recognised as valid, whatever their apparently objective appearance to anyone else.

    This did not seem to resonate with other panel members, who seemed to want their subjective morality to be regarded as the gold standard of normal. When I got home I left them wandering around the straw men of incest, polygamy, sexual hedonism and the demise of the species and public morals that they had thrown in to confuse the issue. Both ends of the argument seemed to want to create moral outrage by failing to recognise the differences between subjective and objective contexts and consequences.

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